Incrustation-preventive



UNITED STATES PATENT, OFFICE.-

GEORGE DOWNIE, OF SALINAS, CALIFORNIA.

lNCRUSTATlON-PREVENTIVE.

SPECIFICATION forming part of Letters Patent No. 277,122, dated May 8,1883.

Application filed October 9, 1882 (No specimens.) I I To all whom it mayconcern Be it known that I, GEORGE DOWNIE, of Salinas, county ofMonterey, State of California, have invented an Improvement in thePrevention and Removal of Scale in Boilers; and I hereby declare thefollowing to be a full, clear, and exact description thereof.

My invention relates to certain improvements in the prevention orremoval of scale in steam-boilers.

It consists in introducing into the boiler an infusion, decoction, orother preparation of encalyptus, either the wood, bark, leaves,blossoms, and capsules, or any portion which will produce the desiredefiect, said infusion either made separately and afterward introducedinto the boiler, prepared in thefeed-Water before its introduction intothe boiler, or prepared within the boiler itself, so as to remove anyscale which may have been already formed, or to so afl'ect the water asto prevent the incrustation of the boiler by any substance which may beheld in solution or suspension in the water which is used in the boiler,and at the same time avoid any injurious effects to the shell of theboiler.

There are many modes of applying the eucalyptus, such as boiling theleaves or other parts, making a cold infusion, or in other waysextracting the desired substance, which may afterward be introduced tothe boiler, as required, either with the feed-water or by a cup orchamber, into which it may be placed, and by suitable cocks admitted tothe boiler; or the leaves or other parts may be placed. in a perforatedtube, basket, or chamber, which can be introduced into the boilerthrough a handhole or other opening, so that the water will act directlyupon the material and extract the valuable portion.

In some cases where there is a heater connected with the boiler I putthe eucalyptus into the hot water which accumulates within the tank, andthe infusion thus made is sent to the boiler by the feed-pump or otherapparatus. By this means the heated water intended for use within theboiler is impregnated with the properties of the eucalyptus, and is thuscaused to part with the scale-forming substanccs,ywhich are deposited ina harmless form and prevented fromsettling as scale.

In case no heater is employed the eucalyptus may be placed directly intothe boiler, or an infusion may be made separately and then supplied tothe boiler when needed, as .before described.

If the eucalyptus, in the form of leaves or fine twigs, be placeddirectly in the boiler, it

,will be preferable to inclose it in a basket or net-work of someconvenient description to prevent its becoming scattered, and so that itmay be easily removedwhe'n it becomes spent.

The charge to be used and the frequency of its renewal-will depend uponthe size of the boiler and the character of the water used, this beingeasily determined by inspection.

I am aware that there is tannin or tannic acid inherent in theeucalyptus, and I am also aware that tannic acid in'various forms hasbeen used to remove scale from boilers. I am also aware that it is awell-reccgnizedfact that tannic acid, when-used for any such purpose,materially injures the boiler in the absence of any other element tocounteract the efl'ect of the tann'ic acid on the metal after it hasperformed its work on the incrustation. :I

do not pretend to set up in this specification any theoryregarding thechemical action of the eucalyptus; but I have demonstrated by longcontinuous and exhaustive experiments that the eucalyptus will removescale from boilers and keep boilers free from scale with out injuringthe shell of the boiler.

Having thus described my invention, whatI claim as new, and desire tosecure'by Letters Patent, is-'- The improved method herein described forpreventing and removing scale from steam boilers, consisting,essentially, in subjecting the interior of the boiler to the action ofan infusion or decoction-ot' eucalyptus, substantiallyas described.

GEORGE DOWNIE. Witnesses:

ELLIS TOMER, A. E. LACEY.

